The invention relates generally to welders, and more particularly to systems and methods for remotely controlling welders using a remote device interposable between a workpiece and an electrode holder and communicating along the welding cable to control various operational parameters otherwise controllable locally from a control panel thereof.
Welding machines, or welders, are known generally and used widely for a variety of welding applications. Engine-driven welders include a combustion engine-driven generator that provides an electric welding current, and static welders obtain welding current from an electrical converter connected to an electrical power supply line. The welding current and other operational parameters of these and other welders are generally selectable and controllable locally from a control panel thereof.
In the Bobcat.TM. 225G Plus engine-driven welder, available from Miller Electric Mfg. Co., an Illinois Tool Works Company, Appleton, Wis., for example, the control panel includes AC/DC selects, polarity reversing selects, and coarse and fine current adjustment controls. The control panel of the Bobcat.TM. 225G Plus engine-driven welder also includes engine choke, start, run/off and low idle controls. Other welders may control some or all of these operational parameters. Static welding machines for example do not require engine choke and idle controls. Other operational parameters include wire feed and auxiliary power controls.
In many applications, especially engine-driven welder applications, welding is performed at a site remote from the welder and the control panel thereof. For convenience, it is known to control a limited number of welding parameters remotely from the control panel. Namely, coarse and fine current adjustment. U.S. Pat. No. 4,216,367 entitled "Wireless Remote Control for Electric Welder" issued Aug. 5, 1980 to Risberg and assigned commonly herewith, for example, discloses a device for remotely controlling weld current in an engine-driven welder to precise percentages of a current value selected previously at the control panel thereof. U.S. Pat. No. 4,216,367 discloses, more particularly, an adjustable rheostat temporarily disposable between a weld stick and workpiece to generate a calibrating current, which flows through the welding cable. The calibrating current is sensed by a current transformer and compared to a previously set and stored welding current reference, which is adjusted automatically after a slight delay to a new desired weld current value.
The present invention is drawn toward advancements in the art of welders, and more particularly to systems and methods for remotely controlling various operational parameters of welders including engine-driven and static welders.
The inventors of the present invention recognize the desirability of remotely starting and stopping welders, particularly engine-driven welders, in addition to or besides controlling weld current. More particularly, remotely starting and stopping welders without any additional cables between the remote site and the control panel thereof. Remote welder control eliminates the necessity of walking back and forth between the control panel and the work-site, which may be located a significant distance therefrom. In some applications, moreover, a plurality of welders are arranged in large banks of welders, which are operated by many welding operators at remote locations. The operators may not know, and it may be very difficult to ascertain, which welder is coupled to a particular welding cable. The advantage of remotely enabling and disabling the welder under these circumstances is self evident. Remote enabling and disabling engine-driven welders is desirable also for reducing engine and generator operation time, thereby extending the useable life thereof as well as other components of the welder. The known prior art however does not teach remote enabling and disabling of welders.
It is therefore an object of the invention to provide novel methods and systems for remotely controlling welders, and more particularly for remotely controlling operational parameters thereof by communicating over a welding cable with a remote device electrically coupleable between a workpiece and an electrode holder.
It is also an object of the invention to provide novel methods and systems for remotely controlling at least one, and preferably more than one, operational parameter of welders otherwise controllable locally from a control panel thereof, including remotely enabling and disabling the welder, remotely choking engine-driven welders, remotely controlling coarse and fine current adjustment, remotely reversing current polarity, among other operational parameters thereof.
It is a more particular object of the invention to provide novel methods and systems for remotely controlling welders having generally a welding cable and an electrode holder for supplying weld current to a workpiece, and one or more operation controls for locally controlling corresponding operational parameters from a control panel thereof. The novel methods and systems include a remote device having one or more operational parameter signal circuits electrically coupleable between the workpiece and the electrode holder for producing corresponding unique operational signals on a welding cable, a sensor circuit for detecting the operational signals and producing corresponding operational sense signals in response thereto, and an operational control circuit for actuating corresponding operation controls of the welder in response to the operational sense signals, thereby remotely controlling operational parameters of the welder corresponding to the unique operational signals produced by the remote device on the welding cable.
It is another more particular object of the invention to provide novel methods and systems for remotely controlling welders with a remote device having one or more constant current source circuits electrically coupleable between the workpiece and the electrode holder for selectively producing one or more corresponding unique operational signals on the welding cable. It is a related object of the invention to provide a battery powered remote device having one or more constant current source circuits coupled to a timer circuit that produces unique intermittent operational signals on the welding cable, whereby the intermittent operational signals reduce battery power consumption.
It is still another more particular object of the invention to provide novel methods and systems for remotely controlling welders having a current transformer sensor circuit for detecting operational signals produced by an alternating carrier wave on the welding cable.
It is a further object of the invention to provide novel methods and systems for remotely controlling welders with a remote device electrically coupleable between a workpiece and an electrode holder, wherein the remote device includes a first electrode coupleable to the workpiece and one or more second electrodes coupleable to the weld stick, or electrode holder, for generating unique operational signals on the welding cable, whereby the second electrodes are readily and accessibly contactable by the electrode holder to selectively remotely control corresponding operational parameters of the welder. It is a related object of the invention to magnetically and electrically couple the first electrode to ferromagnetic workpieces.
These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators.